▎ 摘　　要

NOVELTY - Graphite oxide is produced by oxidizing natural graphite in sulfuric acid, and adding oxidizer (I or II). The solution is injected into a membrane column and sealed. The membrane column is immersed in hydrochloric acid aqueous solution and primarily sonicated. The membrane column is then immersed in ultrapure water and secondarily sonicated, to obtain a graphene oxide aqueous solution. USE - Production of graphene oxide aqueous solution used for manufacturing graphene films and graphene powder (all claimed) used for transparent electrodes, optical fibers, and electrical devices. Can also be used for semiconductor devices. ADVANTAGE - The method provides graphene oxide aqueous solution which enables manufacture of easily peelable high-purity graphene films and high-purity graphene powder. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) manufacture of graphene film, which involves diluting the graphene oxide aqueous solution with pure water, and spin-coating the solution; and (2) manufacture of graphene powder, which involves cooling the graphene oxide aqueous solution and vacuum-drying.